13 results about "Ionization detector" patented technology

The application discloses an ionization chamber of a photo-ionization detector, comprising a negative electrode and a positive electrode, the negative electrode and the positive electrode are arranged in an overlapping mode, an ultraviolet lamp is arranged on one side of the positive electrode or the negative electrode, the negative electrode and the positive electrode are both provided with airflow channels which are in communication with each other, the ultraviolet lamp is located at the inner end of the airflow channels, and the airflow channel edge of the negative electrode or the positive electrode is provided with a high-voltage structure. The high-voltage structure arranged at the airflow channel edge of the negative electrode or the positive electrode can ensure the high collection efficiency of the ionization product of VOCs gas molecules. Therefore, it is unnecessary to additionally apply a higher bias voltage to eliminate the noise influence, and it is also unnecessary to additionally set a complex hardware circuit or a humidity compensation algorithm, so that the manufacturing cost and the failure rate of the photo-ionization detector can be controlled, and the development, debugging and maintenance costs of enterprises can be reduced.

The application discloses a portable environmental air odor monitoring system and a monitoring method based on double columns and negative oxygen ion switching, and belongs to the technical field of environmental monitoring. The monitoring system comprises a sampling assembly, a six-way switching valve, a first chromatographic column, a second chromatographic column, a first four-way switching valve, a second four-way switching valve, a negative oxygen ion generator, a negative oxygen ion mixing cavity, an electric field assembly, a photo-ionization detector, a carrier gas assembly and an oxygen supply assembly. The monitoring method can separate the same sample through two chromatographic columns with different polarities, and can obtain two chromatograms with different retention times. Meanwhile, by controlling the opening and closing of the negative oxygen ion generator, the chemical structure of the measured substance can be modulated, and the chromatogram after oxidation can be obtained. The application is suitable for low-concentration or high-concentration odor monitoring, realizes efficient separation and enhances qualitative ability, and can assist in judging the chemical properties by comparing the chromatographic peak changes or disappearance of the same substance under the non-destructive mode and the oxidation mode.

The invention discloses a modulation type photoionization detector and a trace gas detection method, and relates to the technical field of gas detection. According to the modulation type photoionization detector provided by the invention, carrier gas and sample gas can alternately enter the ionization chamber at a preset frequency through switching of the three-way electromagnetic valve, ion current signals generated by the carrier gas and the sample gas are respectively detected, and a signal response value of gas to be detected can be obtained by subtracting the ion current signals measured in two adjacent times; based on the modulation type photoionization detector, the gas is detected by utilizing a differential noise reduction principle, interference of a small amount of impurity gas and water vapor in carrier gas on a signal response value of the gas to be detected is avoided, and the modulation type photoionization detector is suitable for photoionization detection of trace gas; noise caused by factors such as ultraviolet lamp power fluctuation, environment temperature and humidity changes and circuit thermal changes is effectively filtered out, and the detection signal-to-noise ratio is increased.

The present disclosure describes a detector system for characterizing a therapeutic beam. The detector system may include numerous additional or alternative features and, as an example, may include a detection unit comprising an intensity sensor layer configured to generate a signal in response to ionization events, an x-position sensor layer having a plurality of x-position detector strips and configured to generate a signal in response to one or more ionization events, and a y-position sensor layer comprising a plurality of y-position detector strips and configured to generate a signal in response to one or more ionization events. Signal data may be timestamped and associated with timestamped beam trigger demand data. Processing may allow three-dimensional spatial characterization and fluence characterization of the therapeutic beam. Also disclosed are methods of characterizing a therapeutic beam.

The invention provides a water-gas dual-purpose halogenated olefin sensor, and relates to the technical field of analytical chemistry instruments, the water-gas dual-purpose halogenated olefin sensor comprises a carrier gas pipeline, a clustered membrane in-situ extraction sampling device, a cold trap dehydration device, a gas sample pipeline and a photoionization detector, the clustered membrane in-situ extraction sampling device is connected with the cold trap dehydration device through a conveying pipeline; the clustered membrane in-situ extraction sampling device comprises a container and a membrane sampling device, a liquid sample is contained in the container, the membrane sampling device comprises a clustered membrane, and halogenated olefin in water is extracted into a gas phase; the cold trap dehydration device is used for dehumidifying the gas conveyed in the conveying pipeline to obtain a low-humidity halogenated olefin-containing gas sample, and the low-humidity halogenated olefin-containing gas sample is sent into the photoionization detector for detection through the capillary column; and the gas sample pipeline is directly connected with the ionization detector. The water-gas dual-purpose halogenated olefin sensor disclosed by the invention is high in sensitivity, solves the problems of humidity interference, poor membrane stability and the like, and is suitable for detecting halogenated olefin in underground water.

The invention belongs to the technical field of ionization detectors, and particularly discloses a novel non-radioactive electron capture detector which comprises a shell, a protection cavity is formed in the shell, a discharge electrode, a polarization electrode and a signal electrode are sequentially arranged on the surface of the protection cavity from top to bottom, and a sapphire tube is fixedly connected to the inner wall of the shell. A first air inlet pipe is arranged on one side of the shell, a guide-in pipe communicated with the sapphire pipe is arranged at the bottom of the shell, one side of the surface of the guide-in pipe is communicated with a second air inlet pipe, and the other side of the surface of the guide-in pipe is communicated with a blow-down pipe; the plasma electronegativity is improved through doping gas combination, and the detection sensitivity is remarkably enhanced; the optimized polarization voltage range and the electrode spacing design effectively suppress noise; the anti-pollution capacity of the device adapts to low-purity helium carrier gas, the use cost is reduced, the non-radioactive design is adopted, and the radioactive pollution risk is avoided.

A photo ionization detector (PID) is disclosed. The PID includes a PID lamp having a body and a magnesium fluoride window at an upper end of the body, and a drive electrode surrounding the body of the PID lamp and positioned below the magnesium fluoride window. Further, the drive electrode has elastic properties and thus applies an upward biasing force toward the magnesium fluoride window to maintain a predefined distance between the PID lamp and the signal collection component of the PID.

A photoionization detector sensor comprised of plate, at least one opening in the plate for UV light to pass through, and at least one electrically conductive pattern on at least one of the top and bottom surfaces of the plate. The at least one electrically conductive pattern can include a negative electrical potential pattern comprised of a first material. Further, the negative electrical potential pattern can have a void in its center, and the void can surround the at least one opening. The plate can be comprised of a second material that is different than the first material. The negative electrical potential pattern can be located on at least one of the top or the bottom surfaces, and the at least one electrically conductive pattern can further include an electron collecting electrode pattern on the other of top or bottom surface.

The invention discloses a portable ambient air odor monitoring system and monitoring method based on double columns and negative oxygen ion switching, and belongs to the technical field of environment monitoring. The monitoring system comprises a sampling assembly, a six-way switching valve, a first chromatographic column, a second chromatographic column, a first four-way switching valve, a second four-way switching valve, a negative oxygen ion generator, a negative oxygen ion mixing cavity, an electric field assembly, a photoionization detector, a gas carrying assembly and an oxygen supply assembly. According to the monitoring method, the same sample is separated through two chromatographic columns with different polarities, and two chromatograms with different retention times can be obtained; meanwhile, by controlling the on and off of the negative oxygen ion generator, the modulation of the chemical structure of the measured substance is realized, and a chromatogram after the oxidation reaction is obtained. The method is suitable for monitoring low-concentration or high-concentration peculiar smell, high-efficiency separation is realized, the qualitative ability is enhanced, and the chemical property of the substance can be judged in an auxiliary manner by comparing the change or disappearance condition of the chromatographic peak of the same substance in a lossless mode and an oxidation mode.

A photoionization detector sensor comprised of a plate having top and bottom surfaces and an electrically insulating substrate; at least one opening in the plate for UV light to pass through; a negative electrical potential pattern on at least one of the top and bottom surfaces; and an electron collecting electrode pattern having a wire suspended across the at least one opening. The negative electrical potential pattern includes a linear portion and a polarization plate. The electron collecting electrode pattern further includes a linear portion on the surface opposite the wire. The electrically conductive patterns can further include a grounded potential conductive pattern having a first portion on the top surface and a second portion on the bottom surface.

The utility model discloses an underground water well washing system which comprises a well washing mechanical unit, a water quality measuring unit and a data collecting and processing unit. The well washing mechanical unit comprises a water pump, a water pumping pipe, a water outlet pipe and a water level sensor, the water level sensor is installed on the water pumping pipe, and the water pump, the water level sensor and the water level sensor are all electrically connected with the data collecting and processing unit; the water quality measurement unit comprises a water quality comprehensive measurement device, a PID photoionization detector and an oil-water interface sensor, and the data acquisition and processing unit is used for acquiring and recording data and controlling the flow speed of the water pump and the well washing time. According to the utility model, equipment such as the oil-water interface sensor and the PID photoionization detector can be utilized to carry out water quality preliminary screening before well washing, and according to real-time data flow obtained through preliminary screening, well washing parameters can be dynamically adjusted, the efficiency is improved, unnecessary well washing times are reduced, and time and cost are saved.

An ionization detector provides accurate measurements of high dose rate, short duration radiation pulses required by FLASH radiation therapy procedures by employing high voltages across narrow ionization channels minimizing saturation and polarization effects. Air equivalent polymers may be used to provide the electrodes of the ionization detector for improved accuracy and to resist radiation-induced degradation.

A photoionization detector is disclosed. The photoionization detector includes a detector electrode that outputs a signal, an ultraviolet lamp, a lamp driver that is communicatively coupled to the ultraviolet lamp and configured to turn the ultraviolet lamp on and off in response to a control input, and a controller that is communicatively coupled to the output signal of the detector electrode and the control input of the lamp driver, outputs an indication of a gas detection based on the output signal of the detector electrode, and turns the lamp driver on and off with an on-duty cycle that is less than 10%.